


The Promises

by drrkrbbt



Series: Twitter fics requests [2]
Category: Voltron: Legendary Defender
Genre: AU: Keith and Shiro are brothers, Alternate Universe, Angst, Brogane, Dom/sub Undertones, Face-Fucking, M/M, Sibling Incest
Language: English
Status: Completed
Published: 2017-04-30
Updated: 2017-04-30
Packaged: 2018-10-25 23:59:17
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,393
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10775202
Author URL: https://archiveofourown.org/users/drrkrbbt/pseuds/drrkrbbt
Summary: Keith learns that Shiro has signed up for the Kerberos mission, and he's not too happy about it.





	The Promises

**Author's Note:**

  * For [Kmid](https://archiveofourown.org/users/Kmid/gifts).



*

 

            “So you’re going?” Keith tries very hard to keep the coolness out of his voice, but he’s not doing very well. Shiro seems to visibly shrink before him.

            “I’m sorry,” he says quietly, too ashamed to look Keith in the eye. For a big brother, he doesn’t look very big right now.

            “Why?” This time he’s trying not to sound hurt.

            “It’s my dream,” Shiro replies, still looking at his feet. “And if the mission is successful, I get promoted. We wouldn’t have to worry about money anymore, Keith.” He finally looks up and meets Keith’s gaze. “We wouldn’t have to worry about anything. We’d be set.”

            “I don’t care about money,” Keith huffs.

            “That’s not true,” Shiro prods carefully. “You wouldn’t have to work so hard, and we could buy back mom and dad’s house. We’d be able to go home.”

            Keith sighs, because he knows Shiro is right. The god-awful apartment they’re living in now is cold, clammy, and tiny, and being able to buy back the house they grew up in would be a huge victory for them. They would have their old home back, and no one could come after them.

            “Fine.” Keith rubs over his face, and the anxiety is already bubbling in his chest, but that he doesn’t show Shiro; it has been many years since he has let Shiro know him as anything but headstrong and resourceful. Shiro is the one who needs protecting, who needs shielding, not Keith. The death of their parents hit Shiro much harder than Keith, and Keith has been looking out for his big brother ever since. Shiro is a great leader and he flourishes for each passing day, but only under the supervision of Keith, who controls what Shiro wears, what and when he eats, when he sleeps, and pretty much everything else. Keith didn’t exactly plan to end up like this, controlling every aspect of his big brother’s life, but it works, and Shiro has never complained about it. It makes him feel safe, and he has told Keith that many times when Keith has been unsure of the whole thing. People probably wouldn’t believe it if they knew that big, strong, handsome Shiro is secretly at the mercy of his gangly, grumpy little brother, but then again, Keith and Shiro’s little arrangement is probably the least offensive thing about them.

            “I can’t go with you,” Keith says, sitting up a little straighter in the armchair. He gestures, and Shiro knows what to do. He kneels down in front of the chair, fingers brushing over the cheap, synthetic wool of the carpet.

            “I know,” he whispers. And there’s already a flush spreading on his cheeks. Shiro knows what’s going to happen now, and he already wants it.

            “I can’t look after you when you’re gone,” Keith hums, swallowing down the anxiety that statement provokes. “You know that, don’t you?”

            Shiro nods. He looks down at Keith’s naked feet on the carpet.

            “Will you be okay?” Keith asks him, lifting a foot and placing it on Shiro’s broad shoulder. He can feel how Shiro is practically vibrating in anticipation. “Without me.”

            “No,” Shiro breathes, shaking his head before turning it and pressing his lips to the Keith’s ankle. “But I’ll do my best.”

            “I know you will,” Keith hums. “You always do.” He lets Shiro kiss his foot for a moment, then pulls back and nods at Shiro. Shiro knows what to do and pushes to his feet to get undressed. Keith leans back in the chair, watching as more and more of his big brother’s perfectly smooth skin is revealed until Shiro is finally naked. Keith is always a little stunned every time he lays eyes on his naked brother, because he is surprised by his beauty every time; his big smooth chest, his flat, toned stomach, and his flushed, hard cock. Yeah, it’s already hard, and it twitches when Keith’s gaze glides over it. It likes Keith’s attention, and Keith likes to give it attention. But right now he wants something else.

            “Come here,” he whispers, spreading his legs a bit. Shiro is kneeling again, and he crawls closer on his knees until he’s sitting between Keith’s spread legs. “Take my cock out and get me hard.”

            “Yes,” Shiro breathes, his breath shuddering a bit as he reaches up to undo the front of Keith’s jeans and take his dick out. It’s already swollen a bit, but it’s going to take some more to get him proper hard.

            “Should I use my hands or my mouth, Keith?” Shiro asks him, looking up at him with those adoring eyes that make Keith want to set the world ablaze if that will make Shiro happy.

            “Mouth,” Keith replies, his voice already slightly deeper and rougher than normal, and he sucks in a soft hiss when Shiro leans down to suck his cock into his mouth. When they started doing this, neither of them had had any idea what they were doing, but by now, they know each other’s bodies so well that they know exactly what will get the other off. It is safe and familiar and beautiful.

            “That’s it,” Keith breathes, sliding his fingers through Shiro’s hair and tugging lightly at it. “You always feel so good, Shiro.”

            Shiro moans at the praise, and the vibrations from his deep voice rumble through Keith’s dick, making the blood rush even faster to the tissue. Keith’s fingers tighten in Shiro’s hair, and he pushes Shiro’s head down until Shiro’s nose presses into his pubic hair. Shiro is grunting around him, but Keith knows exactly how far he can push it before Shiro gets uncomfortable, and Keith always takes it right to the edge. He rolls his hips, fucking into Shiro’s warm, amazing mouth and shuddering at the feeling of Shiro’s spit dribbling down onto his balls.

            “Enough,” Keith gasps when Shiro swallows around him and threatens to push him over the edge, and he yanks Shiro’s head away and his mouth off his cock. Shiro’s lips are swollen, and his nose is even bleeding a little from where Keith’s pelvic bone has collided with it, but Shiro doesn’t seem to notice it at all. He just gazes up at Keith through lowered lashes, and Keith knows that Shiro would do anything he told him to right now. Shiro would kill for Keith if Keith asked him to.

            Keith gets to his feet, still keeping one hand buried in Shiro’s hair. He tugs Shiro’s head back to make Shiro arch his neck as far back as it can go.

            “Do you love me?” Keith whispers as he rubs the flushed, swollen head of his dick over Shiro’s sweaty cheek. “Do you love me, brother?”

            “Yes, Keith,” Shiro breathes, lashes fluttering and mouth hanging slightly open. “I love you.”

            “Do you promise me that you’ll come home to me again?” Keith asks before spitting on Shiro’s cheek and sliding his dick through it. He presses down on the shaft, fucking through the mix of spit and blood on Shiro’s cheek.

            “I promise,” Shiro gasps, and Keith doesn’t even have to look to know how painfully hard Shiro is at this point.

            “Good.” Keith gives Shiro’s hair a tug, forcing a groan from Shiro’s mouth. “You can jerk off now.”

            Shiro instantly reaches between his legs to jerk himself off, moaning as Keith’s dick glides over his face.

            “I’m going to fuck you later,” Keith pants, his knees weakening more and more the closer he crawls to his climax. “I want you to be sore and full of my spunk when you leave so you won’t forget me.”

            “I’ll—ah—I’ll never forget you, Keith,” Shiro half-whimpers. “I’ll come back to you, I promise. I’ll never leave you.”

            Keith doesn’t mean to do it, but he lets out a strangled sob when he comes. He doubles over, shuddering as his cock swells against Shiro’s face and releases a hot, thick gush of come that splatters over Shiro’s nose and cheek. It dribbles down his jaw and throat while Shiro breathes out Keith’s name and comes. Keith feels the warm splash of come on his naked foot, and he leans down to kiss Shiro, maybe even suck the life out of both of them so they never have to deal with the outside world again.

 

*

**Author's Note:**

> Disclaimer: I own nothing!


End file.
